Lossless Multipath Table Compression

1. A computer-implemented method comprising: obtaining, using a computer, a plurality of routing rules ordered in a first order; performing, using the computer, a compression algorithm on the plurality of routing rules to compress the plurality of routing rules into a first set of building blocks by determining two or more of the plurality of routing rules that overlap; storing, using the computer, the first set of building blocks in a first multipath table of a network supporting weighted cost multipath routing; re-ordering, using the computer, the plurality of routing rules in a second order; performing, using the computer, the compression algorithm on the re-ordered plurality of routing rules, wherein the performing comprises: compressing the re-ordered plurality of routing rules to a second set of building blocks by determining two or more of the re-ordered plurality of routing rules that overlap; storing, using the computer, the second set of building blocks in a second multipath table; and determining, using the computer, if the second multipath table occupies less memory space than the first multipath table.

2. The method of claim 1 , wherein: a first rule of the plurality of routing rules and a second rule of the plurality of routing rules each includes one or more entries, and performing the compression algorithm on the plurality of routing rules comprises: programming the first rule into the first multipath table by adding the one or more entries of the first rule into the first multipath table; determining that there is an overlap between the second rule and the first rule; and adding, to the first multipath table, one or more remaining entries of the second rule that remain outside the overlap to the one or more entries of the first rule that are previously added to the first multipath table.

3. The method of claim 2 , wherein if the second rule is a complete subset of the first rule, determine that all of the one or more entries of the second rule are already added to the first multipath table.

4. The method of claim 2 , wherein adding the one or more remaining entries of the second rule is performed by appending or pre-pending the one or more remaining entries of the second rule to the one or more entries of the first rule.

5. The method of claim 2 , further comprising: shuffling the one or more entries of the first rule; or shuffling the one or more entries of the second rule.

6. The method of claim 2 , further comprising: scaling up the first rule by a first pre-determined factor such that a traffic load balancing ratio defined by the scaled up first rule is the same as a first traffic load balancing ratio defined by the first rule, wherein the scaling up adds one or more additional entries to the first rule; or scaling up the second rule by a second pre-determined factor such that a traffic load balancing ratio defined by the scaled up second rule is the same as a second traffic load balancing ratio defined by the second rule, wherein the scaling up adds one or more additional entries to the second rule.

7. The method of claim 1 , wherein the compression algorithm is a greedy algorithm.

8. A computer-implemented method comprising: obtaining, using a computer, a plurality of routing rules, wherein a first rule of the plurality of rules includes one or more entries; performing, using the computer, a compression algorithm to compress the plurality of routing rules into a first set of building blocks by determining two or more of the plurality of routing rules that overlap; storing, using the computer, the first set of building blocks in a first multipath table of a network supporting weighted cost multipath routing; scaling up, using the computer, the first rule by adding at least one additional entry to the one or more entries of the first rule; performing, using the computer, the compression algorithm on the plurality of routing rules including the scaled up first rule to compress the plurality of routing rules into a second set of building blocks; storing, using the computer, the second set of building blocks in a second multipath table; and determining, using the computer, if the second multipath table occupies less memory space than the first multipath table.

9. The method of claim 8 , wherein performing the compression algorithm on the plurality of routing rules comprises: programming the first rule into the first multipath table by adding the one or more entries of the first rule into the first multipath table; determining that there is an overlap between a second rule of the plurality of routing rules and the first rule; and adding, to the first multipath table, one or more remaining entries of the second rule that remain outside the overlap to the one or more entries of the first rule that are previously added to the first multipath table.

10. The method of claim 9 , wherein if the second rule is a complete subset of the first rule, determine that all of the one or more entries of the second rule are already added to the first multipath table.

11. The method of claim 9 , wherein adding the one or more remaining entries of the second rule is performed by appending or pre-pending the one or more remaining entries of the second rule to the one or more entries of the first rule.

12. The method of claim 9 , further comprising: shuffling the one or more entries of the first rule; or shuffling the one or more entries of the second rule.

13. The method of claim 9 , wherein the first rule defines a first traffic load balancing ratio and the second rule defines a second traffic load balancing ratio.